A Proof-of-principle Study of Oral Treatment of Non-alcoholic Steatohepatitis With a Novel PDE4 Inhibitor ASP9831

Inclusion Criteria: * NASH, histologically confirmed by a liver biopsy performed within 1 year prior to first dose and randomization * Elevated serum ALT levels Exclusion Criteria: * Hepatic cirrhosis * Other known cause of liver disease * Uncontrolled diabetes mellitis type 2, i.e. HbA1c \> 8.5% * Positive history of tuberculosis or a positive PPD skin test which is not explained by previous BCG vaccination * History of excessive alcohol abuse within 5 years prior to screening or a current average alcohol intake of more than 20 g/day (2 units) for females or more than 30 g/day (3 units) for males * Subject has used drugs associated with steatohepatitis within 6 months prior to screening (corticosteroids, high dose estrogens, methotrexate, amiodarone, anti-HIV drugs, tamoxifen)